The Appendicular Skeleton

The scapula's lateral surface is divided into two grooves by the spine of the scapula, called the:

1. supraspinous fossa (cranial) 2. infraspinous fossa (caudal)

Dogs have up to _____ sesamoid bones in each front paw at the metacarpophalangeal joints

13

Cats have ______ sesamoid bones on the palmar surface of the metacarpophalangeal joints in the front paw.

9

________ is an inflammation of the periosteum over the equine third metacarpal bone; this condition occurs on the cranial surface of the bone

Bucked shins

______ often lack the first carpal bone and occasionally have a fifth distal carpal bone lying lateral and distal to the ulnar carpal bone, for a total of seven or eight carpal bones

Horses

what is the function of the scapula?

It attaches the thoracic limb to the body wall and also serves as the pivot point for the humerus

_____ lack the first metacarpal bone, and their third and fourth metacarpal bones are longer than the outermost bones (the second and fifth) so that only the two middle toes are actually supporting the animal's weight

Pigs

______ have all eight carpal bones.

Pigs

_______ lack the entire first digit, have two dewclaws—the second and fifth digit—and bear weight on the third and fourth digits

Pigs

_________ are similar to pigs, but their dewclaws contain very small, irregular phalanges that reside in soft tissue without articulating with any metacarpal bones. This structure occurs because the second metacarpal is absent, and the fifth metacarpal bone is very small.

Ruminants

describe the scapula?

a flat bone, roughly triangular in shape. -One point of this triangle is directed ventrally, whereas the base of the triangle is directed dorsally. -The medial side of the scapula rests against the rib cage.

Only the _______ carpal bone attaches to muscles

accessory

At the junction of the ilium, ischium, and pubis is a deeply concave joint surface called the __________-

acetabulum

the ________ is where the femur articulates with the pelvis in a ball-and-socket joint that forms the hip

acetabulum

the radius and ulna form part of the thoracic limb known as the forearm or _______

antibrachium

The _________ is composed of the bones of the thoracic and pelvic limbs.

appendicular skeleton

The caudal part of the ilium is called the _____ (or shaft)

body

what is the fibular tarsal bone also referred to as?

calcaneus

Horses have a large third metatarsal bone called the _____ bone

cannon

in horses, the large third metacarpal bone is also known as the _____ bone

cannon

The radius and ulna articulate with the ______ bones distally and act as points of attachment for the muscles that control the elbow and carpal joints

carpal

the distal phalanx in horses is called the

coffin bone

In _____ and ______, the first and second metacarpal bones are missing, the third and fourth are fused into one bone called the cannon bone, and the fifth metacarpal bone is very small

cows / sheep

Carpal bones are a collection of small, somewhat _______, bones that form much of the carpus

cuboidal

Cats have five digits, but the first digit, which has only two phalanges, doesn't bear weight and is thus a _____

dewclaw

All metacarpal bones have the basic long-bone structure: one _________ with two epiphyses, proximal and distal.

diaphysis

The patella allows the tendons of the muscles of the leg's cranial surface to slide easily over the _____ femur and improves the strength and leverage of the muscles that work across the stifle joint

distal

In addition to the patella, carnivores also have small sesamoid bones called _______ that are located caudal to the distal femur

fabellae

The _________ is the thighbone

femur

which tarsal bone is the largest?

fibular tarsal bone (calcaneous)

in the first row of tarsal bones is also the __________ bone

fibular tarsil

Horses completely lack the _____ and ____ metacarpal bones

first / fifth

Dogs and cats have ______ metatarsal bones per hind limb

five

Humans, cats, and dogs each have ______ metacarpal bones

five

In domestic animals, you'll find _____ to _______ tarsal bones, depending on the species, arranged in two rows

five / seven

what type of bone is the scapula?

flat bone, roughly triangular in shape

the front limbs of bats have been modified for ______

flight

the thoracic limbs of dolphins, whales, and seals have evolved into _______

flippers for swimming

The ______ provides space for muscles to attach the scapula to the humerus

fossa

Most bird species contain _______ digits in the pelvic limb

four

just distal to the neck of the scapula, the bone flares out slightly and ends in a concave (dished) region called the ______

glenoid cavity

The gluteal muscles of the pelvic limb attach to the lateral side of the ilium, which is called the _________

gluteal surface

In humans and primates, the thoracic limbs are used primarily for

grasping and manipulating objects

The dorsal border of the body of the ilium is called the ____________

greater ischiatic notch

Cranial to the head of the humerus are two projections called the _________ on the cranial and lateral surface, and the lesser tubercle on the medial surface

greater tubercle

The round, smooth, proximal end that joins with the scapula is called the ______ of the humerus

head

The tarsus is commonly referred to as the ________ in animals

hock joint

Just distal to the scapula is the _______, a long bone with a cylindrical shape

humerus

The _______ serves as a site of attachment for muscles that attach to the scapula and neck to allow the leg to be pulled forward or backward and the head and neck to be pulled down or to the side

humerus

The wing bones consist of the ________, _______, _______, _______, _________, and ______

humerus / radius / ulna / alula bone / metacarpal bones / digits

The wing of the ilium widens near the cranial border like the base of a triangle. This area is called the _______

iliac crest

The _______ is the largest bone in the pelvis

ilium

the sacroiliac joint is the meeting of the _______ of the pelvis and sacrum of the spinal column

ilium

what are the three pelvic bones?

ilium, ischium, pubis

Between the condyles on the tibia you find the __________, which is the the attachment site for some of the ligaments that connect the femur to the tibia

intercondylar eminence

The caudal and lateral angles of the ischium are known as the ______________

ischiatic tuberosities

Caudal and ventral to the ilium lies the _______, which is also a mostly flat bone

ischium

The _______'s position is somewhat horizontal, whereas the ilium is positioned more vertically

ischium

Just proximal and slightly caudal to the condyles of the humerus are two projections that flare out to each side. These are called the ______ epicondyle and ________ epicondyle

lateral / medial

The distal end of the humerus is made up of two condyles—the _________ and the medial trochlea

lateral capitulum

The ________ is a small process at the distal end of the fibula that articulates with the tarsal bones

lateral malleolus

Cranial to the head of the humerus are two projections called the greater tubercle on the cranial and lateral surface, and the ________ on the medial surface

lesser tubercle

Some sesamoid bones increase _________ for the muscle pulling on the tendon in which the sesamoid is embedded; this increased ________ clearly provides a biomechanical advantage to the muscle

leverage

The sacral part of the spine attaches firmly and closely to the medial side of the ilium by means of short and strong _________

ligaments

The metacarpal bones are _______ bones lying side by side

long

The common name for the equine proximal phalanx is the _________

long pastern bone

The distal row of carpal bones is numbered from 1 to 4, starting with the _______ bone and moving laterally

medial

On the medial side of the distal tibia is a bony projection known as the _________, which helps form the joint with the tarsal bones

medial malleolus

The distal end of the humerus is made up of two condyles—the lateral capitulum and the ________

medial trochlea

Distal to the carpal bones are the _______ bones

metacarpal

The epicondyles on the humerus are attachment sites for _______

muscles

_______ and _______ attach the dorsal surface and spine of the scapula to the thoracic spine and the medial surface to the rib cage

muscles / ligaments

the distal sesamoid bone in the horse—commonly called the navicular bone—may develop a type of lameness called ________

navicular disease

The scapula narrows near the ventral point; this is called the _____ of the scapula

neck

A large opening called the ______________- is formed by the ischium and pubis on each side of the pelvis

obturator foramen

Nerves and blood vessels pass through which foramen to reach the inner thighs?

obturator foramen

The _________ is the bony prominence you can feel at your elbow

olecranon process

The most proximal part of the ulna is the __________, which is a very large tuberosity that serves as a point of attachment for the muscles that extend the elbow joint and thereby straighten the leg

olecranon process

the _________ serves as a point of attachment for the muscles on the elbow

olecranon process

Digits that don't bear weight are called _______ (or dewclaws)

paradigits

The ______ is the kneecap

patella

the _______ is slightly oval shaped with a slight point on the distal end

patella

which sesamoid bone in the body is the largest?

patella

In birds, reptiles, and amphibians, the thoracic limb is referred to as the ________

pectoral girdle

The tubercles serve as points of attachment for the ______

pectoral muscles

The ______ limbs support the rear end of the body, and in most land animals the hind limbs are the main source of propulsion and strength when the animal runs or jumps

pelvic

The fundamental bones of the pelvic limb, starting proximally and moving distally, include the following: ________, _______, _______, _______, ________, _________, ________, and _________

pelvic bones / femur / patella / tibia / fibula / tarsal bone / metatarsal bones / phalanges

The seam where the right and left sides of the pelvis come together ventrally is called the _______________

pelvic symphysis

The _______ is a girdle of bones that attaches the spine to the pelvic limbs

pelvis

The bones of each digit are called _______ (singular, phalanx)

phalanges

For a species such as the horse that has a greater need for speed and stability in the legs, fusion of the radius and ulna provides greater stability by _________

preventing this part of the limb from rotating

Each digit except the first is composed of three phalanges: ___________, _________, and _______

proximal / intermediate / distal

The _______ bone lies cranial to the ischium on both sides of the pelvis.

pubis

In horses, the _______ is a long bone slightly flattened on the cranial and caudal surfaces

radius

the lateral capitulum on the humerus articulates with which bone?

radius

The pelvic limbs are directly connected to the axial skeleton by way of the _______ joint

sacroiliac

The tuber sacrale joins the sacrum to form the _______ joint

sacroiliac

the sacroiliac joint is the meeting of the ilium of the pelvis and _______ of the spinal column

sacrum

The ________ is the shoulder blade

scapula

The bones of the thoracic limb, starting closest to the spine and ending near the foot, are the

scapula, humerus, radius, ulna, carpal bones, metacarpal bones, and phalanges

Hoofed animals have a well-developed ridge of cartilage along the dorsal border of the scapula called the _______

scapular cartilage

The pectoral girdle of birds consists of the paired _______, ________, and _______

scapulas / coracoids / clavicles

In addition to the phalanges, the digits also possess _________. These are small nodular bones near a joint

sesamoid bones

Dogs have fused radial and intermediate carpal bones, for a total of _______ carpal bones

seven

unlike the accessory carpal bones, the other carpal bones are pivot points for flexion and extension of the carpal joint and act as ________

shock absorbers

the intermediate phalanx in horses is called the

short pastern bone

In ruminants, the first distal carpal bone is missing, and the second and the third are fused, for a total of _____ carpal bones

six

The lateral surface of the scapula features a ridge, called the ________, which projects laterally along almost the entire length of the bone

spine of the scapula

The shaft of the humerus ________ slightly as it travels distally, following the path of the muscles that travel over the humerus

spirals

in horses, the second and fourth metacarpal bones, commonly called the ________, are vestigial and very small

splint bones

Some species of snakes have vestigial limbs referred to as ______

spurs

The femur articulates distally with the tibia and patella to form the _______

stifle joint

Dogs have a small hole just above the condyle called the ___________

supratrochlear foramen

what is the tibial tarsal bone also referred to as?

talus

The tibia also attaches the muscles that bend the ______ joint distally

tarsal

The ________ are a collection of bones that form the tarsus, which connects the tibia and fibula at the proximal end to the metatarsal bones at the distal end

tarsal bones

the thoracic limbs are connected to the axial skeleton by

the collarbone

where does the humerus articulate with the scapula?

the glenoid cavity

the humerus has knoblike, rounded ends that serve as points of articulation with which bones?

the scapula proximally, and the radius and ulna distally

Horses have only one digit—the _______—that bears all of the weight for the thoracic limb

third

In horses, the _______ metacarpal is the main metacarpal that bears the animal's weight

third

the _________ support the front end of the body and aren't connected to the axial skeleton by bone, only by ligaments and tendons

thoracic limbs

The ________ articulates with the femur to form the stifle joint

tibia

the cranial aspect of the tibia has a ridge called the __________

tibial crest

In the first row of tarsal bones are the _______ bone

tibial tarsal

The _____ bone forms most of the joint with the tibia and fibula

tibial tarsal

At the proximal end of the tibial crest is a projection of bone called the _______, where ligaments connect the patella to the tibia

tibial tuberosity

At the proximal end of the shaft are several projections called _________- that serve as sites of attachment for various muscles, including the gluteals

trochanters

Cranial and just proximal to the condyles lies a curved surface called the ________, where the patella articulates

trochlea

the patella is embedded in muscle tendons that straighten the knee joint, and it slides in the _______ of the femur as these muscles contract and relax.

trochlea

Just distal to the olecranon is the ___________, the curved surface that articulates with the humerus

trochlear notch

the lateral angle of the iliac crest is the _______

tuber coxae

The medial angle of the iliac crest is called the _______

tuber sacrale

When veterinarians take bone marrow biopsies for diagnosis of bone marrow disease, the _________ is often the area biopsied

tuber sacrale

The ________ serve as points of attachment for the pectoral muscles

tubercles

Horses have _______ proximal sesamoid bones located behind the distal articular surfaces of the third metacarpal bone, and one distal sesamoid bone located behind the junction of the intermediate and distal phalanges

two

The first digit is composed of ____ phalanges

two

At its distal end, the _______ tapers and fuses to the radius

ulna

In species in which the ulna remains separate from the radius, which of the two bones is longer?

ulna

The _______ in horses is attached to the caudolateral surface of the radius, and its shaft is incomplete distally

ulna

in dogs and cats, what may be the longest single bone in the body?

ulna

the medial trochlea on the humerus articulates with which bone?

ulna

the limbs attach to the pelvis at the ______ and _______ borders

ventral / lateral

the ilium is a mostly flat, triangular bone that curves outward slightly at the cranial end, which is called the _______

wing